[PATCH v2] purgatory: do not enable vectorization automatically for purgatory compiling

[Baoquan He]

On 03/30/22 at 11:14am, Simon Horman wrote:
> On Tue, Mar 29, 2022 at 06:12:28PM +0800, Baoquan He wrote:
> > Redhat CKI reported kdump kernel will hang a while very early after crash
> > triggered, then reset to firmware to reboot.
> > 
> > This failure can only be observed with kdump or kexec reboot via
> > kexec_load system call. With kexec_file_load interface, both kdump and
> > kexec reboot work very well. And further investigation shows that gcc
> > version 11 doesn't have this issue, while gcc version 12 does.
> > 
> > After checking the release notes of the latest gcc, Dave found out it's
> > because gcc 12 enables auto-vectorization for -O2 optimization level.
> > Please see below link for more information:
> > 
> >   https://www.phoronix.com/scan.php?page=news_item&px=GCC-12-Auto-Vec-O2
> > 
> > Adding -fno-tree-vectorize to Makefile of purgatory can fix the issue.
> > 
> > Signed-off-by: Baoquan He <bhe at redhat.com>
> 
> Thanks, applied.

Thanks, Simon.